Field of the Invention
Embodiments of the present invention relate, in general, to systems and methods for measuring the speed of an object and more particularly to integrating still image and motion picture data of an object with the simultaneous determination of the speed of that object.
Relevant Background
The measurement of an object's speed relative to a stationary point can be accomplished by a variety of devices. It is well known that law enforcement and similar agencies use RADAR and laser measuring equipment to aid in the enforcement of traffic laws. Laser ranging equipment and speed determination is at the forefront of this technology. Laser rangefinders, through a series of pulsed laser bursts, can determine the speed of a vehicle at a range previously unobtainable using RADAR technology. Lasers are extremely accurate and thus, when properly aimed, can be used at ranges far exceeding those of a RADAR system.
As technology evolves, laser based speed detection devices continue to expand the range at which such a device may be employed. Thus, given an accurate aiming system, it is possible for a laser detection device to accurately ascertain the speed of a vehicle at a substantial distance.
To enforce a ticket based on a speed measurement, evidence must generally be presented to accurately identify the vehicle at the precise time the measurement, i.e. violation, occurred and to link the identity of the operator to that instant in time. A vehicle, after all, does not receive a ticket, the operator does. One means to link a speed measurement of a vehicle to the operator is with the use of still and motion imagery.
Synchronizing the exact image with the instance of speed detection, however, is problematic. Simply coupling a still image camera or a motion picture camera to a speed detection device involves considerable processing time. The communication delay among the initiating command to take a speed measurement, determining whether a violation has occurred and capturing either or both a still or motion image at the precise time that violation occurred may render the violation moot. Furthermore, the components comprising such a system are often cost prohibitive.
To accurately and legibly capture the image of a license plate of a vehicle at the employable range of a laser based speed detection device would require a lens/camera system that is extremely expensive. Yet to use a more common and cost effective lens would defeat the use of the laser rangefinder. For example, assume a vehicle's speed could reliably be measured as violating a law at a distance of 2 miles, yet at this range a legible picture of the license plate and the operator cannot be economically produced. By the time that the vehicle is within range of a camera that can produce an image in which the vehicle and the operator can be discerned unquestionably, the vehicle is likely to have slowed and is no longer violating the law. Thus the enforcement agency is faced with a difficult task of linking data indicative of a violation to an operator and/or vehicle that otherwise appears to be obeying the law. These and other challenges are addressed by the invention described hereafter.